First peel the potatoes, then use a box grater to coarsely grate them.
Squeeze the grated potato really tightly to get rid of the excess water, then place it into a large mixing bowl.
Add the flour, diced onion, baking powder, eggs, chopped sage, salt, pepper and garlic granules. Mix well until it is completely combined.
Heat some oil in a large frying pan over a medium heat. Place golf ball sized pieces into the hot oil, use the back of a spoon to press them down into disc shapes.
Cook for about 4-5 minutes on each side until they are golden brown and crisp. Once cooked, place them onto kitchen paper to drain any excess oil.
They are now ready to serve. You can cook them in advance and heat up in the oven if you like.